Any drug used to combat oesophageal reflux[?]. Commonly, following ingestion a 'raft' of alginic acid is created, floating on the stomach contents by carbon dioxide released by the drug. This forms a mechanical barrier to further reflux. Some preparations also contain antacids to protect the oesophagus.
... is also has a grammatical voice: either active, passive or middle. (Middle indicates actions done to something other than the speaker for the speaker's own benefit. The ...